I like it! I like the different weights in the lines. Kinda reminds me of some of the concept art over at Capcom.

The only things that pop out to me as maybe needing some refinement are the hands of both characters. The wrist on what would be the woman's left hand seems to have the wrist bone's slight portrusion a lil out of place. Right now it appears in the center of the wrist where it should be on the side. Other than refining forms on the hands and fingers, I really like it. Hope it helps. Laterz.

Hurri-cane,
Nice pic! I like the line work and appeal of this but, anatomy wise there's posibly a couple funky areas. The head is a little small. To me this feels more like a stylistic choice rather than a mistake. I like it and I'd leave this alone. The neck is kinda long (again, I think you did this on purpose and it looks cool, very exaggerated but, in a good way). The left shoulder of the girl might need to be trimmed down a little. Kinda looks like she's got something growing in there. I'd also maybe work on the breasts a little. They look a little lop sided. And finally, her right hand looks much more massive than the left. Over all, a great piece. I'll be checkin your posts more often from now on . I'd love to see a colored version of this. Very kick ass work. Hope none of this came across badly .

I think it looks cool!
There are some things that maybe could be improved.

The neck looks too long and is too thick.
The upper body is a little bit skewed to the
right(our right) You've also suggested that she is muscular, but the ribs are suggesting that she is very skinny, You could maybe tone it down. The right hand is smaller than the right and looks dead in a way if compared to the left.
Since you've gone so far with doing the legs, are you gonna do the feet too? It'll add weight to it all. The fingers(on all hands) make them look like they have the same length, maybe it's just me...
Looks good
-Mikael